### Abstract

Language | English |
---|---|

Pages | 2401-2408 |

Journal | Journal of Biomechanics |

Volume | 44 |

Issue number | 13 |

DOIs | |

Publication status | Published - 2011 |

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### Cite this

*Journal of Biomechanics*,

*44*(13), 2401-2408. https://doi.org/10.1016/j.jbiomech.2011.06.031

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*Journal of Biomechanics*, vol. 44, no. 13, pp. 2401-2408. https://doi.org/10.1016/j.jbiomech.2011.06.031

**The validity of stability measures: a modeling approach.** / Bruijn, S.M.; Bregman, D.J.; Meijer, O.G.; Beek, P.J.; van Dieen, J.H.

Research output: Contribution to Journal › Article › Academic › peer-review

TY - JOUR

T1 - The validity of stability measures: a modeling approach

AU - Bruijn, S.M.

AU - Bregman, D.J.

AU - Meijer, O.G.

AU - Beek, P.J.

AU - van Dieen, J.H.

PY - 2011

Y1 - 2011

N2 - Measures calculated from unperturbed walking patterns, such as variability measures and maximum Floquet multipliers, are often used to study the stability of walking. However, it is unknown if, and to what extent, these measures correlate to the probability of falling. We studied whether in a simple model of human walking, i.e., a passive dynamic walker, the probability of falling could be predicted from maximum Floquet multipliers, kinematic state variability, and step time variability. We used an extended version of the basic passive dynamic walker with arced feet and a hip spring. The probability of falling was manipulated by varying the foot radius and hip spring stiffness, or varying these factors while co-varying the slope to keep step length constant. The simulation data indicated that Floquet multipliers and kinematic state variability correlated inconsistently with probability of falling. Step time variability correlated well with probability of falling, but a more consistent correlation with the probability of falling was found by calculating the variability of the log transform of the step time. Our findings speak against the use of maximum Floquet multipliers and suggest instead that variability of critical variables may be a good predictor of the probability to fall. © 2011 Elsevier Ltd.

AB - Measures calculated from unperturbed walking patterns, such as variability measures and maximum Floquet multipliers, are often used to study the stability of walking. However, it is unknown if, and to what extent, these measures correlate to the probability of falling. We studied whether in a simple model of human walking, i.e., a passive dynamic walker, the probability of falling could be predicted from maximum Floquet multipliers, kinematic state variability, and step time variability. We used an extended version of the basic passive dynamic walker with arced feet and a hip spring. The probability of falling was manipulated by varying the foot radius and hip spring stiffness, or varying these factors while co-varying the slope to keep step length constant. The simulation data indicated that Floquet multipliers and kinematic state variability correlated inconsistently with probability of falling. Step time variability correlated well with probability of falling, but a more consistent correlation with the probability of falling was found by calculating the variability of the log transform of the step time. Our findings speak against the use of maximum Floquet multipliers and suggest instead that variability of critical variables may be a good predictor of the probability to fall. © 2011 Elsevier Ltd.

U2 - 10.1016/j.jbiomech.2011.06.031

DO - 10.1016/j.jbiomech.2011.06.031

M3 - Article

VL - 44

SP - 2401

EP - 2408

JO - Journal of Biomechanics

T2 - Journal of Biomechanics

JF - Journal of Biomechanics

SN - 0021-9290

IS - 13

ER -